Process for the production of unsaturated bodies from hexose oxidation products



Patented Aug. 14, 1945 UNITED STATES PATENT OFFICE lBOCESS FOR THE PRODUCTION 01' UN- SATURATED BODIES FROM HEXOSE OXI- DATION PRODUCTS William F. Koch, Detroit, Mich. No nmwma nppncaucn August 1:, 194b,

ei'lal N0. 352,41

1 Claim. (Cl. 260-550) Broadly speaking my invention comprehends' First I mix the ethyl ether with fuming and concentrated sulphuric acid (1.8 S. G.) or 80-85% phosphoric acid, just as daired, in the following proportions:

Parts by volume Ethyl ether 1 Concentrated sulphuric acid. 2

Ethyl ether 1 Phosphoric acid (80-85%) 4 or more This mixture is placed in a distilling flask which is connected to a condensing system, the flask being provided with an inlet for the passage of a sweep gas or a carrier gas such as carbon dioxide or sulphur dioxide.

With the distilling flask being heated to raise the temperature of the contained mixture to the condensed material collecting in a flask m the form of liquid ketenes and other unsaturated bodies.

I flnd in practice that it is advantageous to contact the sweep gas with slightly warmed acetaldehyde before the sweep gas enters the distilling flask. In accordance with my invention, the

ethyl ether, when employed as the starting material, is first in part converted to acetaldehyde. Consequently if the sweep gas is saturated with acetaldehyde before it enters the distilling flask. it will be apparent that more ketenes will be produced on a single run than where merely carbon dioxide or sulphur dioxide is employed as the within a temperature range of 100 to 400 C. to

efiect the desired reaction, the sweep gas isrun into the distilling flask to carry the reaction products, resulting from the heating of the mixture, out of the reaction zone as quickly as possible and into the condenser. The reaction products condensing in this condenser collect in a trap at the bottom of the condenser, the specific bodies caught being diacetal of ketene, ketene sulphurous acid addition products and polymers of ketenes-al1 ketene derivatives. The gases not condensing in this condenser pass to another condenser where they are condensed by dry ice, for example, to a very low temperature (80' 0.),

sweep gas. I flnd also that when someacetaldehyde is carried with the sweep gas, the action in the distilling flask is smoother and more uniform and more controllable.

With respect to the use of acetaldehyde as a starting material:

It is to be noted that acetaldehyde reacts with troublesome vigor with concentrated oxidizing mineral acids such as the sulphuric and phosphoric acids above referred to. It is desirable, therefore, to contact the acetaldehyde in dilute form with the acid To this end I may pass gaseous acetaldehyde directly into the acid in the distilling flask, or I may entrain it with the carbon dioxide or sulphur dioxide used as a sweep gas.

I prefer, however, to proceed as follows:

Example B I first dilute the acetaldehyde with ethyl alco- 1101 and ethyl ether, in the following proportions,

or thereabouts:

Parts by volume I then prepare a mixture composed of fuming sulphuric acid and concentrated sulphuric acid in the following proportions:

, Parts by volume Fuming sulphuric acid 1 Concentrated sulphuric acid 2 The two mixtures in the following proportions:

from the three parts employed when usin phuric acid. I Sm In conclusion an for purposes 0! clarity I might add 'thatin connection with the carbon dioxideor the sulphur dioxide gas, the same:

(a) Functions as a sweep gas for the rapid removal of the reaction products from the distilling fl (b) Functions as a carrier'gas for conveying acetaldehyde into the distilling flask;

(0) Forms addition products with the ketenes in the distilling flask to preserve the same against polymerization.

With respect to the ethyl alcohol, the same:

(a) Dilutes the aldehyde to reduce the vigor made in the proportions of materials and in the detailed procedures above described within the purview of my invention.

Thisapplication is a continuation-in-part of my copending application Serial No. 202,469, filed April 16, 1938, Patent 2,257,748.

whatIclaimisz The process oi. producing ketenes and ketene derivatives, which process comprises preparing a mixture of acetaldehyde, one part; ethyl alcohol. one part; and ethyl ether, three parts, by volume, preparin an acid mixture of fuming sulphuric acid, one part, and concentrated sulphuric acid, two parts, by volume, combining the mixtures in the proportions of one part of the aldehyde mixture to three parts of the acid mixture, heating the mixture to Within the temperature range of 100 C. to 400 C., to eflfect chemical reaction of the materials of the mixture, removing the reaction products as formed, and immediately chilling to below pyrolysis temperature.

WILLIAM F. KOCH. 

